drivers/net/ethernet/freescale/fs_enet/mac-fcc.c

   1 /*
   2  * FCC driver for Motorola MPC82xx (PQ2).
   3  *
   4  * Copyright (c) 2003 Intracom S.A.
   5  *  by Pantelis Antoniou <panto@intracom.gr>
   6  *
   7  * 2005 (c) MontaVista Software, Inc.
   8  * Vitaly Bordug <vbordug@ru.mvista.com>
   9  *
  10  * This file is licensed under the terms of the GNU General Public License
  11  * version 2. This program is licensed "as is" without any warranty of any
  12  * kind, whether express or implied.
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/kernel.h>
  17 #include <linux/types.h>
  18 #include <linux/string.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/errno.h>
  21 #include <linux/ioport.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/delay.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/etherdevice.h>
  26 #include <linux/skbuff.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/mii.h>
  29 #include <linux/ethtool.h>
  30 #include <linux/bitops.h>
  31 #include <linux/fs.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/phy.h>
  34 #include <linux/of_address.h>
  35 #include <linux/of_device.h>
  36 #include <linux/of_irq.h>
  37 #include <linux/gfp.h>
  38
  39 #include <asm/immap_cpm2.h>
  40 #include <asm/mpc8260.h>
  41 #include <asm/cpm2.h>
  42
  43 #include <asm/pgtable.h>
  44 #include <asm/irq.h>
  45 #include <asm/uaccess.h>
  46
  47 #include "fs_enet.h"
  48
  49 /*************************************************/
  50
  51 /* FCC access macros */
  52
  53 /* write, read, set bits, clear bits */
  54 #define W32(_p, _m, _v) out_be32(&(_p)->_m, (_v))
  55 #define R32(_p, _m)     in_be32(&(_p)->_m)
  56 #define S32(_p, _m, _v) W32(_p, _m, R32(_p, _m) | (_v))
  57 #define C32(_p, _m, _v) W32(_p, _m, R32(_p, _m) & ~(_v))
  58
  59 #define W16(_p, _m, _v) out_be16(&(_p)->_m, (_v))
  60 #define R16(_p, _m)     in_be16(&(_p)->_m)
  61 #define S16(_p, _m, _v) W16(_p, _m, R16(_p, _m) | (_v))
  62 #define C16(_p, _m, _v) W16(_p, _m, R16(_p, _m) & ~(_v))
  63
  64 #define W8(_p, _m, _v)  out_8(&(_p)->_m, (_v))
  65 #define R8(_p, _m)      in_8(&(_p)->_m)
  66 #define S8(_p, _m, _v)  W8(_p, _m, R8(_p, _m) | (_v))
  67 #define C8(_p, _m, _v)  W8(_p, _m, R8(_p, _m) & ~(_v))
  68
  69 /*************************************************/
  70
  71 #define FCC_MAX_MULTICAST_ADDRS 64
  72
  73 #define mk_mii_read(REG)        (0x60020000 | ((REG & 0x1f) << 18))
  74 #define mk_mii_write(REG, VAL)  (0x50020000 | ((REG & 0x1f) << 18) | (VAL & 0xffff))
  75 #define mk_mii_end              0
  76
  77 #define MAX_CR_CMD_LOOPS        10000
  78
  79 static inline int fcc_cr_cmd(struct fs_enet_private *fep, u32 op)
  80 {
  81         const struct fs_platform_info *fpi = fep->fpi;
  82
  83         return cpm_command(fpi->cp_command, op);
  84 }
  85
  86 static int do_pd_setup(struct fs_enet_private *fep)
  87 {
  88         struct platform_device *ofdev = to_platform_device(fep->dev);
  89         struct fs_platform_info *fpi = fep->fpi;
  90         int ret = -EINVAL;
  91
  92         fep->interrupt = irq_of_parse_and_map(ofdev->dev.of_node, 0);
  93         if (fep->interrupt == NO_IRQ)
  94                 goto out;
  95
  96         fep->fcc.fccp = of_iomap(ofdev->dev.of_node, 0);
  97         if (!fep->fcc.fccp)
  98                 goto out;
  99
 100         fep->fcc.ep = of_iomap(ofdev->dev.of_node, 1);
 101         if (!fep->fcc.ep)
 102                 goto out_fccp;
 103
 104         fep->fcc.fcccp = of_iomap(ofdev->dev.of_node, 2);
 105         if (!fep->fcc.fcccp)
 106                 goto out_ep;
 107
 108         fep->fcc.mem = (void __iomem *)cpm2_immr;
 109         fpi->dpram_offset = cpm_dpalloc(128, 32);
 110         if (IS_ERR_VALUE(fpi->dpram_offset)) {
 111                 ret = fpi->dpram_offset;
 112                 goto out_fcccp;
 113         }
 114
 115         return 0;
 116
 117 out_fcccp:
 118         iounmap(fep->fcc.fcccp);
 119 out_ep:
 120         iounmap(fep->fcc.ep);
 121 out_fccp:
 122         iounmap(fep->fcc.fccp);
 123 out:
 124         return ret;
 125 }
 126
 127 #define FCC_NAPI_RX_EVENT_MSK   (FCC_ENET_RXF | FCC_ENET_RXB)
 128 #define FCC_NAPI_TX_EVENT_MSK   (FCC_ENET_TXB)
 129 #define FCC_RX_EVENT            (FCC_ENET_RXF)
 130 #define FCC_TX_EVENT            (FCC_ENET_TXB)
 131 #define FCC_ERR_EVENT_MSK       (FCC_ENET_TXE)
 132
 133 static int setup_data(struct net_device *dev)
 134 {
 135         struct fs_enet_private *fep = netdev_priv(dev);
 136
 137         if (do_pd_setup(fep) != 0)
 138                 return -EINVAL;
 139
 140         fep->ev_napi_rx = FCC_NAPI_RX_EVENT_MSK;
 141         fep->ev_napi_tx = FCC_NAPI_TX_EVENT_MSK;
 142         fep->ev_rx = FCC_RX_EVENT;
 143         fep->ev_tx = FCC_TX_EVENT;
 144         fep->ev_err = FCC_ERR_EVENT_MSK;
 145
 146         return 0;
 147 }
 148
 149 static int allocate_bd(struct net_device *dev)
 150 {
 151         struct fs_enet_private *fep = netdev_priv(dev);
 152         const struct fs_platform_info *fpi = fep->fpi;
 153
 154         fep->ring_base = (void __iomem __force *)dma_alloc_coherent(fep->dev,
 155                                             (fpi->tx_ring + fpi->rx_ring) *
 156                                             sizeof(cbd_t), &fep->ring_mem_addr,
 157                                             GFP_KERNEL);
 158         if (fep->ring_base == NULL)
 159                 return -ENOMEM;
 160
 161         return 0;
 162 }
 163
 164 static void free_bd(struct net_device *dev)
 165 {
 166         struct fs_enet_private *fep = netdev_priv(dev);
 167         const struct fs_platform_info *fpi = fep->fpi;
 168
 169         if (fep->ring_base)
 170                 dma_free_coherent(fep->dev,
 171                         (fpi->tx_ring + fpi->rx_ring) * sizeof(cbd_t),
 172                         (void __force *)fep->ring_base, fep->ring_mem_addr);
 173 }
 174
 175 static void cleanup_data(struct net_device *dev)
 176 {
 177         /* nothing */
 178 }
 179
 180 static void set_promiscuous_mode(struct net_device *dev)
 181 {
 182         struct fs_enet_private *fep = netdev_priv(dev);
 183         fcc_t __iomem *fccp = fep->fcc.fccp;
 184
 185         S32(fccp, fcc_fpsmr, FCC_PSMR_PRO);
 186 }
 187
 188 static void set_multicast_start(struct net_device *dev)
 189 {
 190         struct fs_enet_private *fep = netdev_priv(dev);
 191         fcc_enet_t __iomem *ep = fep->fcc.ep;
 192
 193         W32(ep, fen_gaddrh, 0);
 194         W32(ep, fen_gaddrl, 0);
 195 }
 196
 197 static void set_multicast_one(struct net_device *dev, const u8 *mac)
 198 {
 199         struct fs_enet_private *fep = netdev_priv(dev);
 200         fcc_enet_t __iomem *ep = fep->fcc.ep;
 201         u16 taddrh, taddrm, taddrl;
 202
 203         taddrh = ((u16)mac[5] << 8) | mac[4];
 204         taddrm = ((u16)mac[3] << 8) | mac[2];
 205         taddrl = ((u16)mac[1] << 8) | mac[0];
 206
 207         W16(ep, fen_taddrh, taddrh);
 208         W16(ep, fen_taddrm, taddrm);
 209         W16(ep, fen_taddrl, taddrl);
 210         fcc_cr_cmd(fep, CPM_CR_SET_GADDR);
 211 }
 212
 213 static void set_multicast_finish(struct net_device *dev)
 214 {
 215         struct fs_enet_private *fep = netdev_priv(dev);
 216         fcc_t __iomem *fccp = fep->fcc.fccp;
 217         fcc_enet_t __iomem *ep = fep->fcc.ep;
 218
 219         /* clear promiscuous always */
 220         C32(fccp, fcc_fpsmr, FCC_PSMR_PRO);
 221
 222         /* if all multi or too many multicasts; just enable all */
 223         if ((dev->flags & IFF_ALLMULTI) != 0 ||
 224             netdev_mc_count(dev) > FCC_MAX_MULTICAST_ADDRS) {
 225
 226                 W32(ep, fen_gaddrh, 0xffffffff);
 227                 W32(ep, fen_gaddrl, 0xffffffff);
 228         }
 229
 230         /* read back */
 231         fep->fcc.gaddrh = R32(ep, fen_gaddrh);
 232         fep->fcc.gaddrl = R32(ep, fen_gaddrl);
 233 }
 234
 235 static void set_multicast_list(struct net_device *dev)
 236 {
 237         struct netdev_hw_addr *ha;
 238
 239         if ((dev->flags & IFF_PROMISC) == 0) {
 240                 set_multicast_start(dev);
 241                 netdev_for_each_mc_addr(ha, dev)
 242                         set_multicast_one(dev, ha->addr);
 243                 set_multicast_finish(dev);
 244         } else
 245                 set_promiscuous_mode(dev);
 246 }
 247
 248 static void restart(struct net_device *dev)
 249 {
 250         struct fs_enet_private *fep = netdev_priv(dev);
 251         const struct fs_platform_info *fpi = fep->fpi;
 252         fcc_t __iomem *fccp = fep->fcc.fccp;
 253         fcc_c_t __iomem *fcccp = fep->fcc.fcccp;
 254         fcc_enet_t __iomem *ep = fep->fcc.ep;
 255         dma_addr_t rx_bd_base_phys, tx_bd_base_phys;
 256         u16 paddrh, paddrm, paddrl;
 257         const unsigned char *mac;
 258         int i;
 259
 260         C32(fccp, fcc_gfmr, FCC_GFMR_ENR | FCC_GFMR_ENT);
 261
 262         /* clear everything (slow & steady does it) */
 263         for (i = 0; i < sizeof(*ep); i++)
 264                 out_8((u8 __iomem *)ep + i, 0);
 265
 266         /* get physical address */
 267         rx_bd_base_phys = fep->ring_mem_addr;
 268         tx_bd_base_phys = rx_bd_base_phys + sizeof(cbd_t) * fpi->rx_ring;
 269
 270         /* point to bds */
 271         W32(ep, fen_genfcc.fcc_rbase, rx_bd_base_phys);
 272         W32(ep, fen_genfcc.fcc_tbase, tx_bd_base_phys);
 273
 274         /* Set maximum bytes per receive buffer.
 275          * It must be a multiple of 32.
 276          */
 277         W16(ep, fen_genfcc.fcc_mrblr, PKT_MAXBLR_SIZE);
 278
 279         W32(ep, fen_genfcc.fcc_rstate, (CPMFCR_GBL | CPMFCR_EB) << 24);
 280         W32(ep, fen_genfcc.fcc_tstate, (CPMFCR_GBL | CPMFCR_EB) << 24);
 281
 282         /* Allocate space in the reserved FCC area of DPRAM for the
 283          * internal buffers.  No one uses this space (yet), so we
 284          * can do this.  Later, we will add resource management for
 285          * this area.
 286          */
 287
 288         W16(ep, fen_genfcc.fcc_riptr, fpi->dpram_offset);
 289         W16(ep, fen_genfcc.fcc_tiptr, fpi->dpram_offset + 32);
 290
 291         W16(ep, fen_padptr, fpi->dpram_offset + 64);
 292
 293         /* fill with special symbol...  */
 294         memset_io(fep->fcc.mem + fpi->dpram_offset + 64, 0x88, 32);
 295
 296         W32(ep, fen_genfcc.fcc_rbptr, 0);
 297         W32(ep, fen_genfcc.fcc_tbptr, 0);
 298         W32(ep, fen_genfcc.fcc_rcrc, 0);
 299         W32(ep, fen_genfcc.fcc_tcrc, 0);
 300         W16(ep, fen_genfcc.fcc_res1, 0);
 301         W32(ep, fen_genfcc.fcc_res2, 0);
 302
 303         /* no CAM */
 304         W32(ep, fen_camptr, 0);
 305
 306         /* Set CRC preset and mask */
 307         W32(ep, fen_cmask, 0xdebb20e3);
 308         W32(ep, fen_cpres, 0xffffffff);
 309
 310         W32(ep, fen_crcec, 0);          /* CRC Error counter       */
 311         W32(ep, fen_alec, 0);           /* alignment error counter */
 312         W32(ep, fen_disfc, 0);          /* discard frame counter   */
 313         W16(ep, fen_retlim, 15);        /* Retry limit threshold   */
 314         W16(ep, fen_pper, 0);           /* Normal persistence      */
 315
 316         /* set group address */
 317         W32(ep, fen_gaddrh, fep->fcc.gaddrh);
 318         W32(ep, fen_gaddrl, fep->fcc.gaddrh);
 319
 320         /* Clear hash filter tables */
 321         W32(ep, fen_iaddrh, 0);
 322         W32(ep, fen_iaddrl, 0);
 323
 324         /* Clear the Out-of-sequence TxBD  */
 325         W16(ep, fen_tfcstat, 0);
 326         W16(ep, fen_tfclen, 0);
 327         W32(ep, fen_tfcptr, 0);
 328
 329         W16(ep, fen_mflr, PKT_MAXBUF_SIZE);     /* maximum frame length register */
 330         W16(ep, fen_minflr, PKT_MINBUF_SIZE);   /* minimum frame length register */
 331
 332         /* set address */
 333         mac = dev->dev_addr;
 334         paddrh = ((u16)mac[5] << 8) | mac[4];
 335         paddrm = ((u16)mac[3] << 8) | mac[2];
 336         paddrl = ((u16)mac[1] << 8) | mac[0];
 337
 338         W16(ep, fen_paddrh, paddrh);
 339         W16(ep, fen_paddrm, paddrm);
 340         W16(ep, fen_paddrl, paddrl);
 341
 342         W16(ep, fen_taddrh, 0);
 343         W16(ep, fen_taddrm, 0);
 344         W16(ep, fen_taddrl, 0);
 345
 346         W16(ep, fen_maxd1, 1520);       /* maximum DMA1 length */
 347         W16(ep, fen_maxd2, 1520);       /* maximum DMA2 length */
 348
 349         /* Clear stat counters, in case we ever enable RMON */
 350         W32(ep, fen_octc, 0);
 351         W32(ep, fen_colc, 0);
 352         W32(ep, fen_broc, 0);
 353         W32(ep, fen_mulc, 0);
 354         W32(ep, fen_uspc, 0);
 355         W32(ep, fen_frgc, 0);
 356         W32(ep, fen_ospc, 0);
 357         W32(ep, fen_jbrc, 0);
 358         W32(ep, fen_p64c, 0);
 359         W32(ep, fen_p65c, 0);
 360         W32(ep, fen_p128c, 0);
 361         W32(ep, fen_p256c, 0);
 362         W32(ep, fen_p512c, 0);
 363         W32(ep, fen_p1024c, 0);
 364
 365         W16(ep, fen_rfthr, 0);  /* Suggested by manual */
 366         W16(ep, fen_rfcnt, 0);
 367         W16(ep, fen_cftype, 0);
 368
 369         fs_init_bds(dev);
 370
 371         /* adjust to speed (for RMII mode) */
 372         if (fpi->use_rmii) {
 373                 if (dev->phydev->speed == 100)
 374                         C8(fcccp, fcc_gfemr, 0x20);
 375                 else
 376                         S8(fcccp, fcc_gfemr, 0x20);
 377         }
 378
 379         fcc_cr_cmd(fep, CPM_CR_INIT_TRX);
 380
 381         /* clear events */
 382         W16(fccp, fcc_fcce, 0xffff);
 383
 384         /* Enable interrupts we wish to service */
 385         W16(fccp, fcc_fccm, FCC_ENET_TXE | FCC_ENET_RXF | FCC_ENET_TXB);
 386
 387         /* Set GFMR to enable Ethernet operating mode */
 388         W32(fccp, fcc_gfmr, FCC_GFMR_TCI | FCC_GFMR_MODE_ENET);
 389
 390         /* set sync/delimiters */
 391         W16(fccp, fcc_fdsr, 0xd555);
 392
 393         W32(fccp, fcc_fpsmr, FCC_PSMR_ENCRC);
 394
 395         if (fpi->use_rmii)
 396                 S32(fccp, fcc_fpsmr, FCC_PSMR_RMII);
 397
 398         /* adjust to duplex mode */
 399         if (dev->phydev->duplex)
 400                 S32(fccp, fcc_fpsmr, FCC_PSMR_FDE | FCC_PSMR_LPB);
 401         else
 402                 C32(fccp, fcc_fpsmr, FCC_PSMR_FDE | FCC_PSMR_LPB);
 403
 404         /* Restore multicast and promiscuous settings */
 405         set_multicast_list(dev);
 406
 407         S32(fccp, fcc_gfmr, FCC_GFMR_ENR | FCC_GFMR_ENT);
 408 }
 409
 410 static void stop(struct net_device *dev)
 411 {
 412         struct fs_enet_private *fep = netdev_priv(dev);
 413         fcc_t __iomem *fccp = fep->fcc.fccp;
 414
 415         /* stop ethernet */
 416         C32(fccp, fcc_gfmr, FCC_GFMR_ENR | FCC_GFMR_ENT);
 417
 418         /* clear events */
 419         W16(fccp, fcc_fcce, 0xffff);
 420
 421         /* clear interrupt mask */
 422         W16(fccp, fcc_fccm, 0);
 423
 424         fs_cleanup_bds(dev);
 425 }
 426
 427 static void napi_clear_rx_event(struct net_device *dev)
 428 {
 429         struct fs_enet_private *fep = netdev_priv(dev);
 430         fcc_t __iomem *fccp = fep->fcc.fccp;
 431
 432         W16(fccp, fcc_fcce, FCC_NAPI_RX_EVENT_MSK);
 433 }
 434
 435 static void napi_enable_rx(struct net_device *dev)
 436 {
 437         struct fs_enet_private *fep = netdev_priv(dev);
 438         fcc_t __iomem *fccp = fep->fcc.fccp;
 439
 440         S16(fccp, fcc_fccm, FCC_NAPI_RX_EVENT_MSK);
 441 }
 442
 443 static void napi_disable_rx(struct net_device *dev)
 444 {
 445         struct fs_enet_private *fep = netdev_priv(dev);
 446         fcc_t __iomem *fccp = fep->fcc.fccp;
 447
 448         C16(fccp, fcc_fccm, FCC_NAPI_RX_EVENT_MSK);
 449 }
 450
 451 static void napi_clear_tx_event(struct net_device *dev)
 452 {
 453         struct fs_enet_private *fep = netdev_priv(dev);
 454         fcc_t __iomem *fccp = fep->fcc.fccp;
 455
 456         W16(fccp, fcc_fcce, FCC_NAPI_TX_EVENT_MSK);
 457 }
 458
 459 static void napi_enable_tx(struct net_device *dev)
 460 {
 461         struct fs_enet_private *fep = netdev_priv(dev);
 462         fcc_t __iomem *fccp = fep->fcc.fccp;
 463
 464         S16(fccp, fcc_fccm, FCC_NAPI_TX_EVENT_MSK);
 465 }
 466
 467 static void napi_disable_tx(struct net_device *dev)
 468 {
 469         struct fs_enet_private *fep = netdev_priv(dev);
 470         fcc_t __iomem *fccp = fep->fcc.fccp;
 471
 472         C16(fccp, fcc_fccm, FCC_NAPI_TX_EVENT_MSK);
 473 }
 474
 475 static void rx_bd_done(struct net_device *dev)
 476 {
 477         /* nothing */
 478 }
 479
 480 static void tx_kickstart(struct net_device *dev)
 481 {
 482         struct fs_enet_private *fep = netdev_priv(dev);
 483         fcc_t __iomem *fccp = fep->fcc.fccp;
 484
 485         S16(fccp, fcc_ftodr, 0x8000);
 486 }
 487
 488 static u32 get_int_events(struct net_device *dev)
 489 {
 490         struct fs_enet_private *fep = netdev_priv(dev);
 491         fcc_t __iomem *fccp = fep->fcc.fccp;
 492
 493         return (u32)R16(fccp, fcc_fcce);
 494 }
 495
 496 static void clear_int_events(struct net_device *dev, u32 int_events)
 497 {
 498         struct fs_enet_private *fep = netdev_priv(dev);
 499         fcc_t __iomem *fccp = fep->fcc.fccp;
 500
 501         W16(fccp, fcc_fcce, int_events & 0xffff);
 502 }
 503
 504 static void ev_error(struct net_device *dev, u32 int_events)
 505 {
 506         struct fs_enet_private *fep = netdev_priv(dev);
 507
 508         dev_warn(fep->dev, "FS_ENET ERROR(s) 0x%x\n", int_events);
 509 }
 510
 511 static int get_regs(struct net_device *dev, void *p, int *sizep)
 512 {
 513         struct fs_enet_private *fep = netdev_priv(dev);
 514
 515         if (*sizep < sizeof(fcc_t) + sizeof(fcc_enet_t) + 1)
 516                 return -EINVAL;
 517
 518         memcpy_fromio(p, fep->fcc.fccp, sizeof(fcc_t));
 519         p = (char *)p + sizeof(fcc_t);
 520
 521         memcpy_fromio(p, fep->fcc.ep, sizeof(fcc_enet_t));
 522         p = (char *)p + sizeof(fcc_enet_t);
 523
 524         memcpy_fromio(p, fep->fcc.fcccp, 1);
 525         return 0;
 526 }
 527
 528 static int get_regs_len(struct net_device *dev)
 529 {
 530         return sizeof(fcc_t) + sizeof(fcc_enet_t) + 1;
 531 }
 532
 533 /* Some transmit errors cause the transmitter to shut
 534  * down.  We now issue a restart transmit.
 535  * Also, to workaround 8260 device erratum CPM37, we must
 536  * disable and then re-enable the transmitterfollowing a
 537  * Late Collision, Underrun, or Retry Limit error.
 538  * In addition, tbptr may point beyond BDs beyond still marked
 539  * as ready due to internal pipelining, so we need to look back
 540  * through the BDs and adjust tbptr to point to the last BD
 541  * marked as ready.  This may result in some buffers being
 542  * retransmitted.
 543  */
 544 static void tx_restart(struct net_device *dev)
 545 {
 546         struct fs_enet_private *fep = netdev_priv(dev);
 547         fcc_t __iomem *fccp = fep->fcc.fccp;
 548         const struct fs_platform_info *fpi = fep->fpi;
 549         fcc_enet_t __iomem *ep = fep->fcc.ep;
 550         cbd_t __iomem *curr_tbptr;
 551         cbd_t __iomem *recheck_bd;
 552         cbd_t __iomem *prev_bd;
 553         cbd_t __iomem *last_tx_bd;
 554
 555         last_tx_bd = fep->tx_bd_base + (fpi->tx_ring - 1);
 556
 557         /* get the current bd held in TBPTR  and scan back from this point */
 558         recheck_bd = curr_tbptr = (cbd_t __iomem *)
 559                 ((R32(ep, fen_genfcc.fcc_tbptr) - fep->ring_mem_addr) +
 560                 fep->ring_base);
 561
 562         prev_bd = (recheck_bd == fep->tx_bd_base) ? last_tx_bd : recheck_bd - 1;
 563
 564         /* Move through the bds in reverse, look for the earliest buffer
 565          * that is not ready.  Adjust TBPTR to the following buffer */
 566         while ((CBDR_SC(prev_bd) & BD_ENET_TX_READY) != 0) {
 567                 /* Go back one buffer */
 568                 recheck_bd = prev_bd;
 569
 570                 /* update the previous buffer */
 571                 prev_bd = (prev_bd == fep->tx_bd_base) ? last_tx_bd : prev_bd - 1;
 572
 573                 /* We should never see all bds marked as ready, check anyway */
 574                 if (recheck_bd == curr_tbptr)
 575                         break;
 576         }
 577         /* Now update the TBPTR and dirty flag to the current buffer */
 578         W32(ep, fen_genfcc.fcc_tbptr,
 579                 (uint) (((void *)recheck_bd - fep->ring_base) +
 580                 fep->ring_mem_addr));
 581         fep->dirty_tx = recheck_bd;
 582
 583         C32(fccp, fcc_gfmr, FCC_GFMR_ENT);
 584         udelay(10);
 585         S32(fccp, fcc_gfmr, FCC_GFMR_ENT);
 586
 587         fcc_cr_cmd(fep, CPM_CR_RESTART_TX);
 588 }
 589
 590 /*************************************************************************/
 591
 592 const struct fs_ops fs_fcc_ops = {
 593         .setup_data             = setup_data,
 594         .cleanup_data           = cleanup_data,
 595         .set_multicast_list     = set_multicast_list,
 596         .restart                = restart,
 597         .stop                   = stop,
 598         .napi_clear_rx_event    = napi_clear_rx_event,
 599         .napi_enable_rx         = napi_enable_rx,
 600         .napi_disable_rx        = napi_disable_rx,
 601         .napi_clear_tx_event    = napi_clear_tx_event,
 602         .napi_enable_tx         = napi_enable_tx,
 603         .napi_disable_tx        = napi_disable_tx,
 604         .rx_bd_done             = rx_bd_done,
 605         .tx_kickstart           = tx_kickstart,
 606         .get_int_events         = get_int_events,
 607         .clear_int_events       = clear_int_events,
 608         .ev_error               = ev_error,
 609         .get_regs               = get_regs,
 610         .get_regs_len           = get_regs_len,
 611         .tx_restart             = tx_restart,
 612         .allocate_bd            = allocate_bd,
 613         .free_bd                = free_bd,
 614 };